Our modern society demands that individuals constantly absorb large amounts of varied information, and there are so many information sources today that many people have to manage the information they receive so as to avoid information overload. Also, in our increasingly mobile society, there is a need to receive the information in a convenient manner while the user is at home, at the office or on the go and even at times when the user's hands and eyes are otherwise occupied. A number of systems have been proposed to provide subscribers with up to date information culled from many sources, in accord with criteria selected by the subscribers based on their individual interests.
For example, U.S. Pat. No. 4,554,418 to Toy discloses a system that continuously monitors a stream of input data, such as financial or stock information. The subscriber submits a list of specific information, such as names of securities of interest. When the list of specific information and monitored data correspond to preselected criteria, for example when the system recognizes that the input data stream includes the selected named securities, a subscriber-specified contact process occurs. Such a specified process may be updating a historical file maintained on the selected subject matter, notification by telephone or computer, or performance of predetermined functional calculations. While this type of system does provide customers with desired information, the ability to receive the information is limited to some type of hardwired (fixed) access, by the need to call in from a normal telephone or communicate via a computer.
U.S. Pat. No. 4,812,843 to Champion, III et al. describes a communication system capable of continuously updating information on a variety of subscriber selected subjects. Primarily, the patent deals with updated traffic information, although the text suggests application to other types of information, including the news. A subscriber inputs DTMF tone codes to select particular information of interest, such as a desired route. The communications system provides the subscriber with updated information reports from information gathered in a database. The system supplies the updated information to the subscriber, in one embodiment by playing pre-recorded voice messages for reception via mobile or landline telephone. The patent discloses alternate embodiments which send data for display on a computer system or a pager.
Similarly, U.S. Pat. No. 5,398,021 to Moore teaches transmission of sports, stock, weather and other news-like data through a paging system. A subscriber database stores records identifying the communication services subscribed to by the party associated with each paging receiver.
Prior systems, such as those suggested to by Champion and Moore, do provide services to send information on subscriber selected topics and some mobility, but the information is transmitted and presented in text form on a computer or a pager display. This is quite adequate in some applications, for example when the subscriber is sitting at a terminal at home or in the office or the subscriber is waiting in a lounge at a transportation terminal. However, there are many situations where the subscriber would like to receive the information but can not use her hands to activate the terminal or look at the terminal for an extended period to read a display. For example, while driving a car a subscriber can not read long news messages presented on a pager display. However, if presented in a convenient form, the subscriber may still want to receive the information at such times.
Devices also have been developed to present users information in audible form. In many situations, a user can listen to the audible presentation while engaged in other activities.
For example, U.S. Pat. No. 5,444,768 to Lemaire et al. discloses a portable computer device for audio reproduction of messages. The device includes a telephone line interface, such as a modem, for receiving digitized messages from a central facility. The central facility downloads textual data messages through the telephone network and the interface, for storage in random access memory. A microprocessor executes text-to-speech conversion rules to provide amplitude and pitch information to excite a digital filter within a speech processor, to create synthetic speech output from the textual data messages. The Lemaire et al. device includes a limited number of tape recorder like switches to activate start/stop, scan and rewind functions for message playback. Portability of the device is limited by the need for a physical connection to the telephone line.
As illustrated by the Lemaire et al. patent, text transmission and text to speech converters are known. However, to produce a high quality synthetic speech output, the text to speech conversion requires a complex speech synthesizer. For example, a company called AccuVoice has developed a 1.5 Mbyte vocabulary of recorded human speech samples, for a text to speech converter. The vocabulary includes all of the phonemes, diphones and triphones of human speech as well as all possible permutations thereof for different inflections and the like. A computer using the AccuVoice vocabulary controls a digital signal processor to play back stored copies of the phonemes, diphones and triphones in a volume and order controlled by a text to speech conversion algorithm. The program for converting text to speech, using the stored vocabulary of phonemes, diphones and triphones, requires additional memory. Although this approach provides adequate speech for computer applications, the memory requirements for the program and the vocabulary are too large for incorporation in a small portable terminal device. As such, systems like that disclosed by Lemaire et al. or the AccuVoice system are not readily adaptable to personal communication services, which sometimes require communications to small portable terminal devices.
U.S. Pat. No. 5,594,779 to Goodman discloses a mobile audio on demand system. Users transmit program selections to a service provider, and the service provider transmits selected audio program information to the users' mobile terminals. The system utilizes cellular telephone communications to transmit the selected audio information in digitized, compressed form. In one implementation, the terminal device may receive the audio data via a high data rate channel and store the compressed information in memory. The compressed audio data may then be retrieved and decoded by a decoder/encoder, and presented to the user at a selected time. The Goodman system does enable some mobility, but there is no provision for receiving and processing text messages. Also, the network transmits digitized speech messages, which requires large amounts of storage in the terminal and may require a relatively large bandwidth if there is a desire to send the messages in real time or at rates faster than real time.
As shown by the above discussion of the prior art, a need still exists for systems and processing techniques for obtaining subscriber desired information and efficiently supplying that information to the subscriber's terminal, in a format facilitating audio presentation thereof to the subscriber.
More specifically, a need exists for a system that will cull selected textual information from a variety of sources and convert that text information to a format that is easily transmitted and stored in a variety of terminal devices, some of which may be small and portable. The terminal devices should provide a high quality speech type audible output of the information. The bandwidth and memory requirements must be kept low to make the service economical and to minimize the cost of the portable terminal. For similar reasons, the processing that the terminal must perform on the received information to produce the speech output also should be minimized, thereby eliminating the need for complex and expensive text to speech conversion equipment and/or software in the typical end user's terminal.